Distributed Optimization using Ant Colony Optimization in a Concrete Delivery Supply Chain

The timely production and distribution of rapidly perishable goods such as ready-mixed concrete is a complex combinatorial optimization problem in the context of supply chain management. The problem involves several tightly interrelated scheduling and routing problems that have to be solved considering a trade-off of production and delivery costs. This paper applies a novel supply chain management paradigm, the distributed optimization, to a real-world case of a concrete delivery supply chain. The production of concrete in several production centers and the distribution of concrete are modeled as job shop problems, where each problem is solved using Ant Colony Optimization. The management methodology consists of allowing each system to exchange information concerning intermediate optimization results through pheromone matrices. In this way, each system finds its own optimization solution based on the information provided by the other systems. A simulation example shows that the proposed coordination mechanism improves the supply chain performance, when compared to another management approach, where both problems are optimized using hybrid methods combining meta-heuristics with constructive heuristics.